1. Field of the Invention
This invention relates to a measuring device for measuring workplaces and more particularly to a measuring device which includes a base frame with a workpiece receiver to receive a workpiece to be measured, and at least one measuring unit to measure the workpiece.
2. Discussion of Prior Art
Such measuring devices are already well known in the state of the art. Thus there are, for example, so-called portal measuring devices which are usually constructed as follows. They include a base frame in the form of a baseplate, to which a workpiece receiver is fastened. By means of this, a workpiece to be measured can be fastened to the baseplate. A portal measuring unit is fastened to the baseplate, for measuring the workpiece, and includes two guides which are fastened laterally of the baseplate, and on which a portal is guided which completely spans the baseplate. The portal can be moved along the baseplate over the guides. The spanning portion of the portal has, for its part, guides on which a slide can be moved transversely of the baseplate. In addition, guides are also provided in the slide. By means of the guides, a measuring arm, with a sensing head located on the measuring arm, can be moved up and down. Thus the sensing head can be moved in three mutually orthogonal directions by means of the above-described mechanism of the portal measuring unit. By means of the position of the sensing head, a workpiece to be measured can be measured in the x-, y- and z-directions.
Furthermore, so-called stand measuring units are also known from the state of the art. The stand measuring devices are essentially distinguished from the portal measuring devices solely in the design of the measuring unit. In contrast to a portal measuring device, the measuring unit in this case has a stand which runs on a guide fastened laterally of the base frame, so that the stand can be moved along the baseplate. The stand is in turn provided with guides, so that a slide can be moved up and down on it. The slide is furthermore provided with guides, by means of which a horizontally oriented measuring arm, with a head fastened to it, can be moved transversely of the baseplate. Workpieces can likewise be measured in three mutually orthogonal directions, x, y and z, by means of the said stand measuring device.
The special feature of the measuring devices known from the state of the art is seen to be that the measuring devices are rigidly fastened in their position. Portal measuring devices, for example, have a measuring arm which is oriented perpendicularly to the baseplate and is thus lowered onto the workpiece to be measured, and therefore can measure measurement points which are difficult to reach, such as, for example, lateral bores in a workpiece, only by the use of relatively expensive sensing heads. In particular, problems arise when different workplaces with differing geometry are frequently measured with one and the same measuring device, since for this purpose many special sensing heads often have to be provided.
The present invention thus has as its object to develop the known measuring devices in such a manner that the measurement, with one and the same measuring device, of different workplaces having differing geometries is thereby simplified.
The object is attained according to the invention by a measuring device for measurement of workplaces including a base frame, having a workpiece receiver for receiving a workpiece to be measured, and at least one measuring unit for measurement of a workpiece, wherein the measuring unit can be arranged in at least two different positions.
The measuring device for measuring a workpiece can be brought into at least two different positions. The particular advantage arises from this that the measuring unit can be arranged, corresponding to the workpiece to be measured, in such a manner that the point on the workpiece to be measured can be reached by the sensing head as easily as possible. Furthermore, two or more measuring units may be installed in the measuring device, according to requirements, so that on the one hand each of the measuring units can optimally measure certain regions of the workpiece to be measured, and on the other hand that the total time for the measurement of a workpiece is reduced, since two or more measuring units measure simultaneously.
In a first embodiment of the measuring device, the measuring unit can be rigidly fastened to the base frame in at last two different positions. To change the position, it is thus necessary to release the rigid connection and to rigidly fasten the measuring unit again, in another position. The rigid connection between the measuring units and the base frame can be produced by fastening the measuring unit to at least one portion the base frame, which fixes the measuring unit in its position. The portion which fixes the measuring unit can have very varied embodiments, and can for example be provided in the form of side members which are arranged laterally of the measuring unit. The measuring unit can be rigidly connected to the side members by fastening means such as screws, for example. The side members can however also be provided in the form of narrow, support surfaces on which the measuring units are placed and to which the measuring units are screwed.
In a second embodiment according to the invention, the measuring unit is movably fastened to the base frame of the measuring device. The base frame here has special fittings by means of which the measuring unit can be moved into at least two different positions. These fittings can, for example, be guides, along which the measuring unit can be pushed. The guides can be either straight or have a curved shape. A hydraulic lifting device, for example, can also be used, which raises or lowers the measuring unit and which advantageously has an additional mechanism, likewise controlled hydraulically, for tilting the measuring unit in at least one direction.